1. Field of the Invention
The present invention concerns computer-related methods systems and mediums for managing experiments. More specifically, it relates to managing experiments concerning changes in a process, for example processes for controlling semiconductor technology manufacture.
2. Related Art
Machines, materials and processes in most industries are becoming increasingly complex and costly. Meanwhile, a need has arisen for the continuing improvement of processes and of machine and material quality.
Semiconductors and other products are typically manufactured under control of pre-defined processes. These pre-defined processes may be highly complex. For example, a pre-defined manufacturing process for producing semiconductor chips might contain five hundred to seven hundred and fifty steps. Moreover, each of these steps might have several variables, for example six variables, that are significant.
In order to improve manufacturing or test theories, it is often desirable to perform experiments by changing some small portion of the base manufacturing process. For example, an engineer might want to make one of the layers on a semiconductor ten percent thicker. This might entail performing the recipe for that step for an extra 15 seconds, with perhaps some adjustments in subsequent steps. Typically the engineer does not create a new base process including the modifications to adapt to the desired test, since that would be too time consuming.
Unfortunately, such an experiment using conventional techniques requires manual intervention and manual tracking of results. Accordingly, the engineer or operator performing the experiment would obtain a number of semiconductor chips and process them outside of an automated (e.g., production or mock-production manufacturing) environment. Thus, the products on which the experiment is performed need to be removed from the automated environment, which is both time-consuming and allows for the potential introduction of extraneous factors which may ultimately (and inadvertently) affect the results of the experiment. In addition, such removal of the semiconductor chips makes it difficult to coordinate manual tracking of changes or experiment history, and to control experiments and to analyze overall results.
Consequently, for research and development engineers, operators and other users working in factory settings, there remains a need for experiments on changes to existing processes to be flexible, easy and traceable.